The invention relates generally to power-driven conveyors and more particularly to conveyors that sort parcels off the side onto chutes.
In various industries, such as in package- and parcel-handling, sorting conveyors are used to sort parcels off one or both sides onto discharge chutes. Gravity roller conveyors or flat-faced slides that decline downward from the sides of the sorting conveyor are examples of two kinds of discharge chutes. Parcels diverted off the sorting conveyor at high speeds can become airborne. In a typical gravity roller conveyor, each of the parallel rollers extends across the full width of the chute. An airborne parcel that lands on the metal rollers can slide axially along the rollers and flip up over the rail at the side of the chute. A similar result can occur with a flat-faced chute. So both of these kinds of chutes have to be made wide enough to provide a long enough stopping distance for airborne parcels.
Another kind of discharge chute that is used with sorting conveyors is constructed of a mat with shorter rollers arranged in rows and columns. The rollers are mounted on axles to rotate freely in a direction toward the lower end of the chute. Some of the rollers near the upper end of the chute in the parcel-landing zone have high-friction peripheries to help slow the parcels upon landing. But because the high-friction rollers are at the same height as the other rollers, which are low friction, the parcels that land on the low-friction rollers have their preferred divert trajectories altered before the entire parcel is over the chute.